Originally Posted by
Burton
Those are nice lights Colleen! But yeah - that lower voltage (7.4V) draws a higher amperage to produce those lumens and will be harder on the batteries. Have you looked at RC batteries at all? I have a couple 11.1V 6.6Ah packs that will support a 150A draw continuously. Complete overkill, but I wanted them for testing multiple lightheads. Leads on those are 12AWG silicone coated and the packs are available in different voltages and are still small enough to fit in a pocket.
Current draw was one reason I decided to go with something outside the bicycle industry myself. 10W 900 lumen P7 units with projector lenses and oversized heat sinking will draw only 0.75A each at 12V, so stacking 4 to 6 of them still doesn't even get a battery warm.
I actually did consider the higher current battery. Two of my AW batteries went Looney Tune on me at the time. One kept shutting off while the other drop to 1.4v for no apparent reason. I stripped out the PCB and the bare batterries were fine. I had another set that was bought at the same time with the same amount of cycle so I decided to use those in a pack.
I also had to consider the safety of the higher current batteries. Since part of my commute involve taking a train that goes underground, I thought about the "what if" scenerio if there were a short in my wire or battery system while I was on the train. Not many places for me to dump the pack while in a underground tunnel
Hence, I chosed the other chemistry battery.